THE POLLINATOR STUDY:
Bees, Wasps, and Yellow Jackets
Honeybees
Honeybees were found at all fields sites, but they were more frequent at some farms than others. Three of the farms visited always had honeybees. Two of those sites had known bee hives close-by. The other three farms had honeybees some days and not others. This appeared to be tied to what was blooming in the field. Two of these farms had Roundup applications made during the study period and this virtually eliminated flowering and honeybee visits.
Honeybees are of particular importance to Christmas tree growers if an insecticide application needs to be made. Insecticides cannot be applied if honeybees are actively foraging in an area. Though the amount of insecticides use in Christmas tree continues to decline, growers do have to treat for some pests. One or two insecticide applications are typically made every year when trees are nearing harvest. Smaller trees seldom require an insecticide application.
In some instances, growers can apply the insecticide at night using tractor driven airblast mistblowers. This greatly reduces the risk of harm to bees as the material is dry by the time bees start to forage in the morning. When applications need to be made during the day with a high pressure sprayer, growers can use herbicides such as Roundup to burn back flowers prior to treating, and then make the insecticide application when bees are no longer foraging in the area.
For more information on insecticide use in Fraser fir Christmas trees and what pests are being controlled see Pesticides Used in Christmas Trees.
For more information on how Christmas tree growers can protect bees see Tips for Keeping Bees Safe.
Other Bees
Bumblebees were also found in every field and were common until the first frosts. Other bees that were frequently observed include sweat bees and yellow-faced bees. One field had frequent catches of green sweat bees, far more than any other. Carpenter bees were also regularly observed, particularly in one field that had an abundance of primroses.
Wasps and Yellow Jackets
When most people think of wasps, they think of something that stings and is dangerous. But most wasps do not sting and are actually quite important to the environment. Many insects are eaten or parasitized by wasps. Parasitic wasps lay eggs in their insect hosts where the larvae grows and develops. There are well over 100,000 different species of these types of wasps.
Wasps of all sorts were observed through the summer and fall in Christmas tree farms. Stinging wasps and yellow jackets were observed visiting flowers and even the Christmas trees themselves. Some Christmas tree pests such as Cinara aphids produce honeydew which attract yellow jackets especially. Yellow jackets and hornets make nests in Christmas trees which are a danger to people working in trees. But by the time these trees are harvested, these wasps are no longer present.
Parasitic wasps were also often found in sweeps of groundcovers around trees. The farms that appeared to have the most diversity of wasps were those where field borders were allowed to grow up in flowering plants. Many of these plants such as ironweed and Joe Pye weed are too tall to allow to grow unchecked among the Christmas trees themselves, but in field borders, they brought in many pollinators.
Photo Gallery
The following photographs were taken from the study site with as accurate an identification as possible.
was most commonly found.
It was only found once so far in the study.
and feeding in the nectaries as this one is doing on primrose.
The male of the eastern carpenter bee has a bright yellow patch on its face.
Though large, it is not aggressive.
The markings are 1 mm apart.
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